Lock screen blur not working with two monitors on Wayland and scaling
Affected version
- OS: Archlinux, up-to-date (2020-03-14)
- Gnome Shell & Mutter, v3.36.0
- AFAIK this only affects Wayland
Bug summary
So, I know this is a very special bug, but I think it should be addressed anyway.
If you use two or more monitors, and at least one monitor uses scaling (doesn't matter if you're using fractional scaling, e.g. 150%, or "normal" scaling with 200%), and then lock the screen, the lock screen seems to have the wrong resolution and also the background blurring of the wallpaper doesn't work.
I have two monitors, "left" (24") and "right" (14"), both with a resolution of 1920x1080 pixel. "Left" is at 100%. "Right" uses fractional scaling at 150%. If I lock my desktop, the lock-screen looks like the following picture:
The picture has the wrong resolution of 4800x1620 pixel (instead of 1920+1294x1080 pixel → 3214x1080 pixel), and the background image is only shown at the top left on each monitor.
Steps to reproduce
- Use two monitors
- Use Wayland
- Configure at least one monitor to use scaling other than 100%. The bug also occurs if you set both monitors to, e.g., 125%; or even if you use a single monitor with fractional scaling
- Lock the screen